Method of producing cartons having metal tearing edges



Feb. 10, 1953 R. M. BERGSTEIN METHOD OF' PRODUCING CARTONS HAVING METALTEARING EDGES Filed Feb. 1, 1950 2 SHEETS--SHEET l FIlLZ;

IN VEN TOR.

ATTORNEYS.

Feb. l0, 1953 R, M. BERGSTEIN 2,628,179

METHOD OF PRODUCING CARTONS HAVING METAL TEARING EDGES Filed Feb. l,1950 2 SHEETS- SHEET 2 Patented Feb. i0, 1953 METHGD OF PRODUCINGCARTONS HAVING l METAL TEARING EDGES Robert M. Bergstein, Wyoming, OhioApplication February 1, 1950, Serial No. 141,697V

14 Claims. (Cl. 154-118) My invention has to do with the provision cipaperboard boxes or other structures having an edge portion againstwhich a iiexible material may be torn. Boxes of this type are commonlyused to contain rolls ci flexible material such, for example, as waxed.paper, the material being Withdrawn from the carton and torn from theroll in such length as may be required for a particular use. Y

The primary objects of my invention are tw fold: the provision of boxesor other structures having tear strips at a lesser cost than hashitherto been found necessary in the practical art, and the provision ofspecific improvements in boxes or other structures provided with tearstrips; all as Will hereinafter be set forth.

These and the more specific objects of my invention, which will beapparent to the skilled worker in the art upon reading thesespecifications or will be later pointed out, I accomplish by thatprocedure and in those structures of which I shallnow describe certainexemplary embodiments with reference to the drawings which form a parthereof, and in which:

Figure 1 is a plan View of a blank for one form of box produced inaccordance with my invention.

Figure 2 is a partial sectional view of the tear strip portion andadjacent body Wall taken along the section line 2 2 of Figure 1.

Figure 3 is a transverse cross-sectional view of an erected box formedfrom the blank of Figure l and containing a roll of dispensablematerial.

Figure e is a plan View of a box insert designed to be employed with apaperboard carton of otherwise conventional construction..

Figure 5 is a transverse cross-sectional view of a paperboard cartonfitted With theinsert of Figure 4 and containing a roll of dispensablematerial Figure 6 is a plan view of vanother typeof ineert. p

Figure 7 is a longitudinal section through the erected insert aspositioned in a carton, the carton and the roll of dispensablematerial-'being indicated in dot-dash lines. Y

Figure 8 is a transverse cross-sectional view of a carton having a typeof doubletear strip .hereinafter described. y

Figure 9 is a vertical longitudinal section diagrammatic in nature of anapparatus suitable for associating tear strip material with paperboardfor the formation either of cartons or of inserts. The section respondsto section line .9-9ofFigure10- Y I -1` 1 sii) Figure 10 is a partialhorizontal section related to the section line IU-I of Figure 9 andshowing most of the apparatus elements of that figure in plan.

Figure l1 is a plan view of a double blank illustrating a preferred modeof manufacture of the blank element of Figure i.

Figure 12 is a longitudinal vertical section. partially diagrammatic innature, of a series of machine elements especially adapted for theformation of box inserts.

Figure 13 is a plan vievs1 corresponding to Figure l2.

Figure 14 is a plan View of one form of blank from which the structureillustrated in Figure 8 can be made.

Figure 15 is a plan view cf a blank of the general type of that ofFigure 1 but modified as to the nature of the tear strip.

I-litherto in the manufacture of boxes having tear strips, it has beenthe substantially universal -practice to form tear strips from metallicmembers and then attach these metallic members to the edges of a Wall ofa ,carton blank. The operation is expensive and time-consuming,requiring the use of special machinery not only for the attachment ofthe tear strips but also for their initial formation. The tear stripseither present a straight, sharp edge for tearing purposes or a seriesof serrations or teeth. In either event these are located beyond theactual edge of the paperboard of the Wall of the box to which they areattached; and present some danger of injuring the hands of the user. Ihave found that excellent tear strips may be made by methods hereinafterdescribed in detail by involving essentially the adhesive attachment ofa metal strip element to paperboard and the simultaneous severing ofthetwo layers to form the actual tearing edge. Very considerable economiesare effected in my procedure in several ways. The operation of attachinga metal strip is simple end inexpensive, involving only the rolling onof a preformed metallic strip with the interposition of a suitableadhesive, the strip being withdrawn from a continuous 'supply such as aroll which may be formed by slitting a Wide supply. `There are noforming operations performed upon the metal as such and the'entire costof such operations is saved. Since the paperboard and the metallicstrip'. are concurrently severed or cut, the'edge of the strip will bebacked by paperboard adhesively secured to it at its outer or tearingedge. This not only makes the structure safer to use sincefthe.likelihood of scratches and cuts is less, but since the paperboardreinforces the actual cutting edge whether toothed or straight, I amenabled to use thinner gauges of sheet metal in the formation ofadequate tearing strips. Many commercial tear strips hitherto producedmust be wider than mine due to the exigencies of their attachment, andthis amounts to a further saving in metal. It is a feature ci myinvention that when a composite of metal and paperboard is cut or slitin accordance with my invention, two tear strips are concurrently formedwhich, again, represents a substantial economy in cost. The principlesof my invention also lead to the possibility of the manufacture of tearstrip structures especially those designed to serve as inserts instandard paperboard cartons, by the use of fully automatic mechanismwhich is extremely simple and inexpensive, as will hereinafter beexplained in detail.

The nature of the metal andv its thickness do not form necessarylimitations on my invention. As indicated, however, thev actual tearingedge provided by my tear strips is reinforced by paperboard in adhesiveunion with it and thisr enables me to employ thinner metal than would beeffective otherwise. In the practice of my invention, I have found thatexcellent results may be obtained through the use of metal as thin asthat having a thickness of from .003 to .005 in. whereas thecommercially produced formed metal tear strips which are attached asabove indicated to cartons, regularly have a thickness of from .008 to.010 in. Heavier and lighter materials than those indicated above mayalso be used in the practice of my invention; and it will be understoodthat it is within the scopev of my invention to apportion the thicknessof the metal used to the thinness and tear resistance of the dispensableproduct to be torn on the edge. Various metals may be employed includingrelatively soft and non-springy metals such as aluminum and non-hardenedcopper; but I have found that excellent results may be attained throughthe use of light, cold-rolled iron or mild steel especially whenemploying such a material in its work-hardened condition,

Adhering the metal to the paperboard merely involves the use of anadhesive which will form a good and permanent bond with each. There aremany adhesives which will serve. I prefer adhesives which do not set upto a hard and brittle condition but rather maintain a degree ofelasticity in the hardened condition together with a strongcohesiveness. Many commercially available adhesives will serve mypurpose, including animal and vegetable glues, such substances asbitumen, and the like. I have attained excellent results both withthermoplastic adhesives and with those which are water emulsions ordispersions of rubbery and resinous substances. Examples of commerciallyavailable adhesives which are excellent for my purposes are: A naturalrubber latex base adhesive such as the product sold under the nameWond-R- Glu by the American World Chemical Company of St. Louis,Missouri, or an adhesive dispersion, understood to have a syntheticrubber base sold under the name NI-413 by Union Paste Company of HydePark, Massachusetts.

As indicated, in the practice of my invention the metal strip isadhesively united to paperboard and the two are then concurrentlysevered tc form a cutting edge. Severing may be done by dies operatingin a press, by continuous slitting with straight or serrated cutters, orby the operation of cutting and scoring presses such as are employed forthe manufacture of cartons. In the light of this, it will be apparentthat in one procedure I may attach metal strips to a supply ofpaperboard or boxboard designed for the formation of cartons, and thenform cartons from such a supply by ordinary cutting and scoringincluding the cutting of the previously applied metal strip or strips,all cutting and scoring being done at the same time. The paperboard maybe printed either before or after the attachment of the strip or strips.

Yet again, I may form carton blanks complete, then attach my metalstrips to the blanks and afterward cut concurrently the paperboard andthe metal. In this connection, since the cutting of the composite ofpaperboard and metal can be employed' to form two tear strips, it isadvantageous to form the cartons in multiple with corresponding edgesjoined and unsevered. The metal strip may then be applied over thejoined and unsevered edges, after which the operation by which thecomposite of metal and paperboard is cut or slit will serve to separatethe different carton blanks from each other.

Yet again, I may adapt the teachings ofmy invention to the formation ofinserts for cartons which otherwise can be of fully conventional form;and in doing this I may form the inserts both in multiple. andcontinuously.

In cutting the composite of paperboard and metal,A I prefer to cause theknife or die to pass through from the paperboard side. This results in aslight displacement of the cut edge of the metal strip away from thepaperboard side of the composite, thus providing a sharper cutting edgeor in the case of serrations or teeth, a displacement of the ends of theteeth toward the metal side resultingV in their better exposure to thematerial to be torn. By reason of the con tinuous adhesive union of themetal and the paperboard, the teeth remain reinforced throughout theirextent andthe paperboard follows the displacement of the cutting edge orteeth so as to remain as a continuous reinforcement. Since the tearstrip will normally be located at the inside surface of a box or carton,the displacement of the teeth inwardly not only makes the tearing actionmore eiicient, but makes the tear strip as such less likely to presentsharp or jagged edges at the outside of the structure.

The cutting may be done by ordinary cutting rules in a die such as isused for cutting paperboard in the manufacture of cartons. Again, I mayemploy continuous cutters, for example those in which a rotary knifeelement having either a straight or a serrated cutting edge, operatesagainst an anvil roll or else against the conforming edge of anotherrotary element, exerting with the first a shearing action. With the useof relatively thin metal, cutting rules such as areused for paperboardwill last a fairly long timefalthough if the run is long, it may benecessary Ato renew those cutting rules which cut metal before othercutting and scoring rules require rcnewal. It is comparatively easy tocut through the metal and paperboard composite from the metal side; butif as I prefer, the cutting is done from the paperboard side, this maybe found more difficult with such cutting and scoring dies as arecommonly used in the making of paperboard cartons. Indeed, where themetal is relatively heavy and a plurality of cuts is to be made at thesame time, it may be found that the ordinary cylinder type of cuttingand scoring press will not serve. The cutting and scoring, however, orat least that part of it which involves the cutting of metal strips, maybe performed in a moving platen type of platen press, such as theso-called Thompson press where greater cutting pressure may be employed.

It is quite possible, I have found, to form an adequate toothed cuttingedge by cutting through the composite oi' paperboard and metal with thefamiliar nicked cutting rule frequently used for forming a line ofweakening in boxboard. This, of course, does not result in completeseverance of the metal and the boxboard along the line of cut; but thetwo partially severed parts are readily thereafter separated by bendingone or more times until the small connecting portions of the metalbreak. This results in a series of smallr sharp, jagged teeth productiveof an excellent tearing edge, but there is involved the expense of themanipulations of bending, usually performed by hand, to separate theparts. For this reason, I prefer an operation in which the parts can besevered completely in the cutting operation.

Referring now to Figure 1, l have there illustrated an exemplary form ofbox formed of paperboard cut and scored to provide a front wall i, abottom wall 2, a rear wall 3, a top l and a top tuck flap 5 articulatedtogether by the usual score lines in the order named. The front, bottomand back walls are provided with end closure flaps 6, "l, S, s, Iii andH which may be of any form desired and may have interlocks, although asealend form of structure which can be set up about a mandrel isgenerally preferred. The closure flaps l and i l on the ends of the backwall are provided with top flaps l2 and I3 coacting with the top wall 4in forming a top wall closure. The line of articulation between the topwall 4 and the tuck flap 5 may be provided with notches It and l5interlocking with edge portions of the flaps I2 and I3 to hold the boxclosed. Such a construction is conventional and well known in the art.

My structure .has adhesively secured to the free edge of the front walll a metal strip I6 having a cut edge for tearing. The edge may bestraight as shown at il in Figure or it may be slotted and provided withteeth IS as shown in Figure 1.

A cross-section of the edge presenting the tear strip is shown in Figure2. Where the composite of paperboard and metal has been cut in the wayset forth above as preferred, the metal and paperboard are slightlydisplaced to the metal side, as indicated at i9 in Figure 2, givingeither a sharp tooth or a sharp cutting edge as they case may be.

Figure 3 is a transverse cross-sectional view showing the use of theerected structure with a roll 2s of disposable material such, forexample, as wax paper. Like parts have been given like index numerals inFigure 3 and are readily identifiable. It will be noted that thedisposable material issues and is withdrawn from the package between thetuck flap 5 and the edge of the front wall l which provides the tearstrip. The displacement of the teeth or cutting edge inwardly, asillustrated at I@ in Figure 2, helps to retain the edge of disposablematerial from the roll 2d with a portion thereof torn olf, and tends toprevent the loss of the free edge inside the box. It will be understoodthat ordinarily when a length of material is withdrawn from the box andtorn off, the tearing proceeds on a line extending slightly aslant tothe true transverse axis of the length of material so that one edgeportion tends to protrude from the box. The inwardly directed teeth orcutting edge tend to retain the protruding material.

Considering the manufacture of such a structure as is illustrated inFigure 1, I may, as shown in Figures 9 and 10, provide sheets 2| ofboxboard of a size suitable for printing, cutting and scoring in theformation of cartons. These sheets may be caused to move along a. table22 by pins 23 on a. pair of conveyor chains or belts 24, 25 mounted onsuitable sheaves and driven as desired. As indicated in Figure 10, sideguides 2B 2l may be provided. As the sheets move along, one or moremetallic strips 28 from a roll or rolls 29 are coated with adhesive asby a conventional coater 3f! and are pressed by one or more pressurerolls 3l into contact with the sheets 2 l. It will be understood thatthe strips 28 are applied along those predetermined lines in the sheets2! where severance of the strip or strips in the ways hereinabovedescribed will result in the formation of tearing edges at the desiredposition of the carton blanks.

As the treated sheets are fed forwardly beyond the end of the conveyors24, 25, as by pinch rolls 32, the interconnecting portions of themetallic strip or strips 23 may 'ce severed, as by a fly knife 33 andstacked by feeding rolls 34 in a stack 35. ri'he sheets so treated maythen be treated in cutting and scoring presses for the formation ofcartons therefrom. Preferably the sheets will have been printed asdesired before being treated as in Figures .9 and 10; but since it ispossible to print the sheets after the metallic strips have been adheredto them, the skilled worker-n the art will understand from thedescription above that it readily possible to apply one or more metallicstrips to a continuous supply of paperboard, afterwards severing boththe paperboard and the strip or strips .into individual sheets which maybe stacked, as at 35. Again, the continuous supply may be imprinted orprinted, but in the latter event, the fly knife 33 will have to be sotimed with respect to the printed representations on the supply as toform sheets suitable for cutting and scoring.

Yet again, the elements 2i in Figures 9 and 10 may be in the form ofmultiple carton blanks rather than unscored sheets. Such a multiplecarton blank is illustrated in Figure 11 and consists of at least twoblanks A and B, so formed that the top edges of their front walls arejuxtaposed and joined. It is over this juncture that the metallic strip28 is applied as aforesaid. Afterward, the metallic strip is slit or outalong its median line which has the combined result of forming thecutting edge as hereinabove explained, and also of severing of themultiple carton blanks from each other. In this event the cutting of thecomposite of metal strip and paperboard can be accomplished on the samecutting and scoring press by which the multiple carton structures wereformed, or it can be done on other mechanism. The cutting may, forexample, be accomplished on apparatus such as that shown in Figure 9with a continuous cutting element 35 operating against an anvil roll 3?as indicated in dotted lines in that figure.

The principles of my invention are also adapted to the formation ofcutting strip inserts to be inside cartons of conventional construction.One form of insert is illustrated in Figure 4 as consisting of apaperboard body presenting a front wall la, a bottom wall 2a and a backwall 3a, the front wall being provided with a tear strip 55a. in theformation of such lastructure I may employ mechanism such as is shown inFigures 12 and 13. Here a continuous supply 38 of boxboard is withdrawnfrom a roll 39. As it passes between pinch rolls 40, a strip 28a whichhas previously been coatedV with adhesive is pressed to its surface. Arotary cutter il having a cooperating element 42 on the opposite side ofthe supply may be employed to slit the supply midway of the metal strip28a. As indicated above, the continuous cutter may be of the shearingtype, but is preferably of the blade and anvil roll type. The blade 4|may be straight or serrated, For demarking and articulating the portionsla, 2a and 3a from each other, I may employ continuous scoring devices:i3` operating against an anvil roll or rolls 4d. Additional pairs ofpinch rolls 45 and 45 may be used to propel the product which then issevered into the required lengths by the fly knife 47 and stacked as at48.

The Inode of use of inserts of this type is illustrated in Figure 5. Itwill be evident from this figure that the inserts are erected or formedinto U-shape and placed in the erected carton prior to the insertion ofthe roll 20 of dispensa-ble material. The mode of formation of theinserts is cheap and continuous. They may if desired be formed ofpaperboard substantially heavier than that employed for the cartonitself, thus reinforcing the carton, providing a stiffer pack-- age, andif desired permitting the use of thinner boxboard for the carton itself.

Another form oi?V insert is illustrated in Fig urev 6 as comprising apaperboard body having a front wall element lb, to the ends of which endelements i9 and 58 are articulated as shown. The mode of use of thistype of insert is illus* trated in Figure '7 and does not requireextended description. Again, the insert is erected by bending the endelements 49 and 5G at right anglesto the front panel ib; and thestructure is inserted in the carton as before. The engagement of the topportion or lid of the carton with the end elements 49 and 56 will serveto retain the insert in place, Inserts such as those shown in Figure 6may be formed in the same continuous fashion as has been described abovein connection with Figures 12 and 13 and on the same apparatus, with thesubstitution of a transverse scoring device well known in the art forthe longitudinal scoring devices t3, dii.

When boxes are provided with tear strips, it is well understood that thetearing should be done by drawing the material toward, not away from,the tear strip. Nevertheless, the housewife in haste frequently attemptsto tear the material in the wrong direction, in which case the tearstrip can perform no function. 'Fearing the material in the wrongdirection may also be occasioned by the manner in which the box ispicked up from a shelf or support and in which hand. In the practice ofmy invention it is readily possible to'provide a box having a tear stripformed on each of the two meeting edges of a pair of adjacent body wallsso that irrespective of the direction in which the user attempts to tearthe dispensable material, there will always be presented a tear strip inthe right position. A mode and structure for accomplishing this isillustrated in Figures 8 to 14, the latter showing a blank having a rearwall I, a top wall 52, a rear wall 53, a bottom wall 54 and an element55 which is either a tuck flap or a glue flap, preferably the latter.End closure elements 56,

51. 56 and 59. 6D, 6i are articulated respectively to the ends of thebody walls 5l and 52 and 53: and the adjacent closure elements, i. e.55, 57. 58 at the left-hand end of the body walls and 5E), 60, 6 IA atthe right-hand end ofthe body walls are articulated to each other byprolongations of the score lines between the body walls. The closureelements 55. 58, 59 and 5i are provided with diagonal score lines asshown. The body wall 54 is provided with end closure flaps 62 and 63. Informing this carton the metallic strip 64, which is to provide the dualtear strips, is adhesively affixed to the boxboard over the line ofdemarkation between walls 52 and 53. It is slit along its median line asat 65, but the slit terminates at the ends of the body walls 52 and 53.Such a structure may be used as a tuck flap carton, but it is moreconveniently tubed by folding along the lines of articulation betweenbody walls 5| and 52 and body walls 53 and 54 with the adhesive union ofthe flap 55 to the free marginal portion of the body wall 5l. It may beshipped to the packager in this condition. The packager will then erectthe tubular body, close one end of it, insert the roll of dispensablematerial through the opposite end and then close that end. In theparticular form of carton illustrated, in forming an end closure, theclosure portions provided with the diagonal score lines, such as 5S and58, will fold bellowswise with the bellows folded portions disposedbeneath the element 5l. The closure may be completed either byadhesively securing the flap 52 to the outer surface of the element 5l,or by inserting the flap 62 beneath the element 5l wherel it will engagebetween the element 57 and the bellows folds, making a secure closure.

One object of providing end closure elements, articulated to each otheris to make it possible to slit the metallic strip d for the entirelength of the body walls, so that the carton need not be substantiallylonger than the roll of dispensable material which it is to contain.However, if the carton is made somewhat longer than the roll, it willthen be possible to slit the strip 64 for less than the full length ofthe body walls. in which event closure elements, all o which are free ofeach other, may be employed.

In either event a structure is provided for use as illustrated in thecross-sectional View, Figure 8, in which along the line of emergence ofthe dispensable sheet material 65, there is a tear strip 5'! or 58 oneither side of it. Thus, no matter in which direction the user attemptsto tear o' the dispensable material, a cutting or tearing edge will bepresented for the purpose, and it will be quite impossible to tear thesubstance ofi in the wrong direction.

It may be pointed out that in the blank of Figure 14 the unseveredportion of the metallic strip 6d, overlying as it does certain lines offold in the paperboard, tends to maintain the folded condition of thepaperboard in the erected structure which is of Value in maintaining theclosure.

Modifications may be made in my invention without departing from thespirit of it. Having thus described my invention, what I claim az; newand desire to secure by Letters Patent is:

l. A :process of providing a paperboard article lia-ving a reinforcedtearing edge which comprises providing a paperboard member and arelatively narrow strip of thin metal, adhesively securing the narrowmetal strip to said paperboard member, concurrently severing thepaperboard and metal by forming a cut therein extending longitudinallyof the metal strip, whereby to provide at least one metal tearing edgesupported and reinforced bv a lpaperboard member.

2. The process claimed in claim 1 in which the cutting is done bypassing a severing element through the combination from the paperboardside whereby slightly to deflect the paperboard and metal immediatelyadjacent their cut edges.

3. The process claimed in claim l wherein the paperboard element is acut and scored element having articulated parts.

4. The process claimed in claim 1 wherein the paperboard element is acut and scored elemenll having articulated parts, and wherein thescoring of the said vpaperboard body is performed concurrently with thesevering of the metal and paperboard. combination.

5. rhe process claimed in claim 1 wherein the paperboard element is acut and scored element having articulated parts, and in which thepaperboard. extends on both sides of the metal strip and is cut andscored, the severing of the combination of metal strip and paperboardserving to divide the composite into two useful articles, each having atearing edge.

6. The process of claim 5 in which the useful articles are eachpaperboard cartons.

7. A process of making carton inserts with tea-ring edges whichcomprises the steps of moving a continuous supply of paperboard,continuously adhering a narrower metal strip to the paperboardintermediate its edges, scoring the paperboard and slitting the metalstrip and paperboard concurrently along a line intermediate the edges ofthe metal strip, the last two mentioned step-s :being performed inindifferent order, and then severing the treated material intoindividual pieces by cutting it transversely.

8. A process of making articulated paperboard articles with tearingedges which comprises adhering a relatively narrow metal strip torelatively wider paperboard material and thereafter forming at least onearticulated structure from the composite by cutting and scoringincluding forming a cut conjointly through the metal strip and thepaperboard to provide a tearing edge.

9. The process claimed in claim 8 wherein the articulated structure soformed is a paperboard carton.

l0. The process claimed in claim 8 wherein the articulated structure soformed is a paperboard carton, said last mentioned cut being formedalong a line of articulation between body walls of said carton.

l1. The process claimed in claim 8 wherein the articulated structure soformed is a paperboard carton, said last mentioned cut being formed.along a line of articulation between body walls of said carton, saidcarton having body walls in articulation and closure elementsarticulated to the ends of said body walls, adjacent closure elementsbeing joined in a prolongation of the said line of cut, the metal stripbeing unsevered along the line of said joining.

12. The process claimed in claim 8 wherein at least two articulatedstructures are formed concurrently, the cutting of said metal and saidpaperboard concurrently serving to sever said articles from each other.

13. A process of producing cartons having metal tearing edges whichcomprises moving sheets of paperboard in a path, adhering a narrowermetal strip to said paperboard sheets continuously, severing said sheetsfrom each other, and afterward cutting and scoring said sheets to formcarton blanks, including the step of forming a cut through the metalstrip and paperboard concurrently, said cut extending longitudinally ofthe metal strip and acting to form the tearing edge of each carton.

14.The process claimed in claim 13 wherein the last mentioned cut isproduced by passing a cutting element through the composite from thepaper side.

ROBERT M. BERGSTEIN.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 1,023,527 Smith Apr. 16, 19121,499,808 Distin July 1, 1924 2,069,335 Salsberg Feb. 2, 1937 2,115,853Hill May 3, 1938 2,235,623 Ross Mar. 18, 1941 2,237,346 Gilfillon Apr.8, 194.1. 2,284,724 Church June 2, 1942 2,306,178 Meany Dec. 22, 19422,316,469 Thor Apr. 13, 1943 2,323,105 Welch June 29, 1943 2,336,842Broeren et al Dec. 14, 1943 2,425,043 Moore Aug. 5, 1947 2,437,022Fritizinger Mar. 2, 1948 2,555,944 Bergstein Aug. 28, 1951 2,566,249Rainey et al Aug. 28, 1951

1. A PROCESS OF PROVIDING A PAPERBOARD ARTICLE HAVING A REINFORCEDTEARING EDGE WHICH COMPRISES PROVIDING A PAPERBOARD MEMBER AND ARELATIVELY NARROW STRIP OF THIN METAL, ADHESIVELY SECURING THE NARROWMETAL STRIP TO SAID PAPERBOARD MEMBER, CONCURRENTLY SEVERING THEPAPERBOARD AND METAL BY FORMING A CUT THEREIN EXTENDING LONGI-